The present invention relates to a unitary assembly of electronic cards fitted with microcomponents, comprising a base printed circuit card carrying microcomponents and at least one additional card secured thereto, said additional card being smaller in size than the base card and likewise carrying microcomponents.
Numerous consumer appliances are controlled by printed circuit cards carrying electronic microcomponents. The continuing increase in the number of functions that such appliances need to perform has given rise to an increase in the number of microcomponents that are required, and thus to the area necessary for carrying them. Such microcomponents are of varying kinds. Some components have terminal pads distributed at a pitch that is much smaller than the spacing between pads of other kinds of component. When such components are all fixed on the same card, the manufacturing accuracy required for the card is determined by the pitch of the pads of the most difficult components. However, any increase in accuracy gives rise to an increase in the cost of making a card, and that is particularly true when the card is large in size. The cost of cards for use in consumer appliances must be very low, which implies both low manufacturing cost and low reject rate.